Type 'gastroparesis' into a google browser and find the link to the Mayo Clinic. They've got a decent overview of delayed gastric emptying = gastroparesis.
Its is usually that the nerve in your stomach is damaged and you food does not empty into your bowels properly (delayed). But my case is idiopathic, so yours could be caused from something else. When I found out I had gastroparesis I found alot of information the internet. What helped me the most was doing MAJOR diet changes. Make sure that you follow a low residue/low fat diet. Medication, like Domperidone, also helps me alot...